相关论文: Atomic and electronic structures of ternary iron a…
We present a systematic investigation of the electrical, structural, and antiferromagnetic properties for the series of Ba(Fe$_{1-x-y}$Co$_{x}$Rh$_{y}$)$_{2}$As$_{2}$ compounds with fixed $x \approx$ 0.027 and $ 0 \leq y \leq 0.035$. We…
We present a density functional theory investigation of strained Ca$_{0.5}$Sr$_{0.5}$TiO$_3$. We have determined the structure and polarization for a number of arrangements of Ca and Sr in a 2$\times$2$\times$2 supercell. The a and b…
The structure of CO adsorbates on the Rh(110) surface is studied at full coverage using first-principles techniques. The relative energies of different adsorbate geometries are determined by means of accurate structure optimizations. In…
Recently, layered copper chalcogenides Cu2X family (X=S, Se, Te) has attracted tremendous research interests due to their high thermoelectric (TE) performance, which is partly due to the superionic behavior of mobile Cu ions, making these…
We have investigated clean and As-covered zinc-blende GaN (001) surfaces, employing first-principles total-energy calculations. For clean GaN surfaces our results reveal a novel surface structure very different from the well-established…
We present detailed electronic structure calculations for CaFe2As2. We investigate in particular the `collapsed' tetragonal and orthorhombic regions of the temperature-pressure phase diagram and find properties that distinguish CaFe2As2…
The c(6x2) is a reconstruction of the SrTiO3(001) surface that is formed between 1050-1100oC in oxidizing annealing conditions. This work proposes a model for the atomic structure for the c(6x2) obtained through a combination of results…
The structural, magnetic, vibrational and electronic properties of single layer aluminum oxide (AlO2) are investigated by performing state-of-the-art first-principles calculations. Total energy optimization and phonon calculations reveal…
In addition to higher Tc compared with the ubiquitous cuprates for a material composed of a single electronically active layer, the newly discovered LnFeAsO superconductors offer additional compositional variation. In a similar fashion to…
La$_{0.4}$Na$_{0.6}$Fe$_2$As$_2$ single crystals have been grown out of an NaAs flux in an alumina crucible and characterized by measuring magnetic susceptibility, electrical resistivity, specific heat, as well as single crystal x-ray and…
We use transport and neutron scattering to study electronic, structural, and magnetic properties of the electron-doped BaFe$_{2-x}$Ni$_x$As$_2$ iron pnictides in the external stress free detwinned state. Using a specially designed in-situ…
\ We combine density functional theory and molecular dynamics simulations to investigate the impact of Sr concentration and atomic ordering on the structural and ferroelectric properties of (Ba, Sr)TiO$_3$. On one hand, the macroscopic…
We present neutron diffraction analysis of BaFe$_2$(As$_{1-x}$P$_x$)$_2$ over a wide temperature (10 to 300 K) and compositional ($0.11 \leq x \leq 0.79$) range, including the normal state, the magnetically ordered state, and the…
BaNi$_2$As$_2$ exhibits a first order structural transition at 130 K. Understanding this structural transition is a crucial step towards understanding the electronic properties of the material. We present a combined optical spectroscopy and…
We have successfully synthesized a new layered iron oxychalcogenide BaFe2OSe2 single crystal. This compound is built up of Ba and Fe-Se(O) layers alternatively stacked along the c-axis. The Fe-Se(O) layers contain double chains of…
The atomistic structure and energetics of the Sigma 13 (10-14)[1-210] symmetrical tilt grain boundary in alpha-Al2O3 are studied by first-principles calculations based on the local-density-functional theory with a mixed-basis…
The (001) surfaces of cleaved Sr$_3$Ru$_2$O$_7$ and Sr$_2$RuO$_4$ samples were investigated using low-temperature scanning tunneling microscopy and density functional theory calculations. Intrinsic defects are not created during cleaving.…
Structural and optical properties of MBE-grown GaAs(001) surface have been studied by reflection high-energy electron diffraction and single-wavelength ellipsometry under dynamic conditions of ramp heating after desorption of passivating…
We present a combined high-resolution x-ray diffraction and x-ray resonant magnetic scattering (XRMS) study of as-grown BaFe2As2. The structural/magnetic transitions must be described as a two-step process. At T_S = 134.5 K we observe the…
We describe x-ray resonant magnetic diffraction measurements at the Fe K-edge of both the parent BaFe2As2 and superconducting Ba(Fe0.953Co0.047)2As2 compounds. From these high-resolution measurements we conclude that the magnetic structure…